Twelve months after one of the most controversial takeover battles in British corporate history the American food group that bought Cadbury has embarked on a campaign to repair its battered image. In his first major interview, Nick Bunker, the Kraft executive who will run the combined Kraft and Cadbury business in Britain and Ireland, has insisted the Illinois-based group is committed to the philanthropic credo of the Cadbury brand.

He said that a recent trip to Ghana with Fairtrade showed it was serious about Cadbury's pledge to cocoa growers and underlined its own British heritage. The company had been "misunderstood" during the bid battle but accepted many consumers "didn't know who Kraft was".

"We are a big company in the UK now and it is important people know the entity behind the famous brands," he said. "People didn't know who Kraft was and that we had been in the UK for 85 years. They didn't know we had a heritage in the UK and a bigger chocolate business than Cadbury before we bought it."

The acquisition turned Kraft, which makes everything from Dairylea and Philadelphia cheese spreads to Milka and Toblerone chocolate bars, into the world's second largest food group with sales of $48bn (£30.8bn). But its reputation was shredded by its conduct during the hostile takeover, which saw chief executive Irene Rosenfeld go back on a promise to keep open Cadbury's Somerdale plant in Keynsham, near Bristol, days after it won control.

The about-face not only raised and then dashed workers' hopes, but earned Kraft a stern rebuke from the Takeover Panel. It also made Rosenfeld extremely unpopular as she declined to meet concerned MPs and unions and only visited Cadbury's historic base in Bournville for the first time in October.

Kraft is thought to have drafted in advisers to help rehabilitate its image but some of its early efforts look heavy handed. During her whistlestop visit to Birmingham, Rosenfeld, who was named the world's second most powerful woman after Michelle Obama by Forbes magazine, spent several hours with Bunker serving cucumber sandwiches and tea to residents of a Birmingham hostel and ate dinner at the Cadbury World tourist attraction. Although she told local papers the factory was the "heart and soul of Cadbury" she refused to extend a two-year pledge – extracted by MPs on the business select committee in March – not to cut British manufacturing jobs at Cadbury.

After months of sparring, the £11.6bn takeover of Cadbury was finally struck in January with talks on how to knock the two businesses together getting under way in February. "We will go through the process in a timely fashion," said Bunker at the time. "There won't be a big bang. We want to get it right and talk to customers about what integration might mean for them."

The promise to Cadbury's 2,500 factory workers did not extend to the rest of the enlarged group's 7,000 staff in the UK and Ireland. Of the 160 people involved in the Cadbury corporate entity some 120 have left the business. In May, Kraft said it was closing three offices: its headquarters in Cheltenham and satellite offices in Banbury and Sheffield, displacing at least 500 people – including Bunker, who after more than a decade abroad has just settled his two children into school in Britain.

There were "plenty of opportunities" for staff willing to make the 90-minute commute to Uxbridge or 45-minute drive to Bournville, he said, but the company had yet to finalise the number of roles available. "This has affected me as well," he said. "We are still working through the process."

Surprisingly, the main hubs for the enlarged group are former Cadbury sites: Uxbridge and Bournville, which has become the firm's global "centre of excellence" for chocolate, at the expense of a research and development centre in Munich. The Kraft plant in Banbury remains the heart of its coffee business, which includes Kenco and Carte Noir. The former Bird's Custard plant is to receive a near-£16m investment in new production lines, including making Kenco "eco refill" pouches, which have been a big hit in Britain.

Kraft has begun talking to customers, such as the large supermarkets, about how the enlarged group will handle sales accounts, but says the businesses will be remain separate until the IT and other important systems are merged next year. Consumers have nothing to fear as there are emphatically no plans to change the recipe of Dairy Milk or create a Milka hybrid.

Bunker appears frustrated by the focus on "cuts" and insists it will be a growth story: "Cadbury is thriving and will continue to thrive." Consumers have not been put off their favourite chocolate bar by the takeover tussle with British sales of Dairy Milk up nearly 13% this year, according to Nielsen data.

But Bunker's promise to make Cadbury stronger is not helped by the fact he himself was "acquired" when Kraft bought another famous British chocolate maker, Terry's, in 1998 – only for the famous York factory to close in 2005.

He counters that "Terry's is a bigger brand today" but some high-profile senior departures have led to raised eyebrows. Bunker, however claims the lines between the two companies are already beginning to blur, with eight of the 12- strong executive committee from Cadbury and two-thirds of the top 100 managers. (Cadbury was the bigger business).

"There is a lot of emotion around this business [Cadbury] … but when you get these guys in the room and take away the PowerPoint, the people are very similar."